• Journal of Environmental Science International
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• v.24 no.2
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• pp.237-244
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• 2015

This objectives of research are to figure out combustion characteristics with increasing temperature with petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and sawdust, and to exam heating value and ignition temperature for using refused derived fuels(RDFs). After analyzing TGA/DTG, petrochemical sludge shows a rapid weight reduction by vaporing of inner moisture after $170^{\circ}C$. Gross weight reduction rate, ignition temperature and combustion rates represent 68.6%, $221.9^{\circ}C$ and 54.1%, respectively. In order to assess the validity of the RDFs, the petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and waste sawdust. The materials are mixed with 7:3(petrochemical sludge : organic matters)(wt%), and it analyzes after below 10% of moisture content. The ignition temperatures and combustion rates of the waste electric wire, anthracite coal and waste sawdust are $410.6^{\circ}C$, $596.1^{\circ}C$ and $284.1^{\circ}C$, and 85.6%, 30.7% and 88.8% respectively. In heating values, petrochemical sludge is 3,600 kcal/kg. And the heating values of mixed sludge (adding 30% of the waste electric wire, anthracite coal and waste sawdust) each increase up to 4,600 kcal/kg, 4,100 kcal/kg and 4,300 kcal/kg. It improves the ignition temperatures and combustion rates by mixing petrochemical sludge and organic matters. It is considered that the production of RDFs is sufficiently possible by using of petrochemical sludge by mixing wasted organic matters.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.193-204
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• 2020

This experiment was conducted to study the effect of organic fertilizer on the growth of Peucedanum japonicum Thunberg and the change of soil chemical characteristics. The organic matter contents of coffee sludge and dried food waste powder were 44.26 and 51.18%, respectively. These values exceed the organic matter content of organic fertilizers recommended by the Rural Development Administration (RDA) of South Korea by more than 30%. Accordingly, they indicate the possibility of their use as organic fertilizers. The results from the analysis of soil properties after cultivation showed that the organic matter content of coffee sludge amended soils was two-fold higher than that of dried food waste powder amended soils. However, the content of available phosphorus was two times lower in the coffee sludge amendments. It is expected that the dried food waste powder was actively used to decompose organic substances, and that phosphoric acid was added by the soil microorganisms used to decompose organic substances. In terms of Peucedanum japonicum Thunberg growth, leaf discoloration was observed for all treatments except with the standard rate of dried food waste powder. The standard rate of dried food waste powder also produced relatively better results than other treatments with regard to other growth characteristics such as root length (34.08 cm), root diameter (0.78 cm), and fresh root weight (4.77 g plant^-1). Therefore, the standard rate of dried food waste powder produced better results than other treatments and can be used as an organic fertilizer in the growth of Peucedanum japonicum Thunberg.

• Ocean Science Journal
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• v.40 no.2
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• pp.91-100
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• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.5
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• pp.629-636
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• 2012

This study focuses on the feasibility of bio-gas production using anaerobic digestion by measuring methane generation and biodegradability through the BMP test of industrial organic wastes. Organic wastes consist of entrails of pigs and organic residues of rumen generated from slaughter houses, wastewater sludge from slaughter waste water, fish offal and residues of vegetables from public wholesale markets, and wastewater sludge from the process of wastewater treatment in paper mill. The cumulative methane production by BMP test ranges from 149.3 ml/g-VS to 406.6 ml/g-VS and this is similar to methane generation of the normal wastewater sludge and food waste. As a result of measurement of biodegradability, wastewater sludge (S1 ~ S4) is low, ranging from 27.1% to 58.9 % and organic residues of rumen (G1) is low at 49.6 %. In conclusion, it turned out that raising the hydrolysis by various pre-treatments is necessary in order to produce bio-gas by using industrial organic wastes.

• Asian Journal of Turfgrass Science
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• v.5 no.2
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• pp.81-86
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• 1991

The sludge, a waste of brewery industries, was examined for potentials as a natural organic fertilizer (or soil conditioner) for lawn. Trial products were measured for changes of physical, chemical properties in laboratory and seed germination and seedling growth in green house were also tested. The results are as the following:1The sludge from distilled liquor brewery contained high quantity of organic matter which had proper physical and chemical properties for lawn fertilizer (natural organic fertilizer, soil conditioner, top-dressing mix) . It showed good characteristics in handling and capabilities to be developed as commercial products for golf courses. 2.Sludge from beer company needs proper treatment to improve physical properties for futher degradiation. It is because aggregation of the sludge particles prevented microbial activities and changing to soluble form. 3.Green carbon can be used as carbon source for organic fertilizer production using brewery sludge, but it should not contain wood extract which inhibit seed germination and seedling growth.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.6
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• pp.703-712
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• 2010

This study performed to extract operation factors of major organic wastes, which were food wastes and waste activated sludge generated in industries in order to use them as a substrate for bio-H2 production. According to the results of experimental analysis for hydrogen production capacity by various organic concentrations, the hydrogen production yield was the highest at 80 g/L, and the efficiency was improved by the pretreatment of waste activated sludge (acid treatment, alkali treatment). Hydrogen production efficiency was improved by mixing food wastes and waste activated sludge if waste activated sludge was below than 30%, however, it was decreased when it was more than 50%. The impacts of heavy metals on the hydrogen production shows that the inhibition level depends on the concentration of Cr, Zn, and Cu, Fe was able to enhance the hydrogen production.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.238-244
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• 2005

This study performs the pilot-plant experiments to evaluate the effect of the oxygen enrichment on the co-incineration of municipal solid waste and organic sludge from a wastewater treatment facility. The design capacity of the stoker-type incinerator pilot-plant is 150 kg/h. Combustion chamber temperatures were measured as well as the stack gas concentrations, i.e., NOx, CO, and the residual oxygen. The maximum ratio of organic sludge waste to the total waste input is 30%. Also the oxygen-enriched air with 23% of oxygen in supplied air is used for stable combustion. As the co-incineration ratio of the sludge increased up to 30% of the total waste input, the primary and the secondary combustion chamber temperature was decreased $to900^{\circ}C$ (primary combustion chamber), $750^{\circ}C$(secondary combustion chamber), respectively, approximately $200^{\circ}C$ below the incineration temperature of the domestic waste only (primary: $1,100^{\circ}C$, secondary: $950^{\circ}C$). However, if the supplied air was enriched to 22% oxygen content in air, the incinerator temperature was high enough to burn the waste mixture with 30% sludge, which has the heating value of 1,600 kcal/kg.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.25-31
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• 1999

Energy recovery technology from municipal solid waste has been increasingly established in many countries. Anaerobic treatment of municipal sewage sludge has low digestion efficiency because of low organic loading rate of sewage sludge. The purpose of this study was to evaluate anaerobic biodegradability of food waste which was based on organic loading rate and seeding rate. From the results of anaerbic biodegration, the optimum condition for seeding rate was turn out over 40%, which did not inhibition of methane production.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.1
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• pp.61-70
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• 2012

Feasibility of co-digestion was investigated by a series of anaerobic batch experiments using sewage sludge, swine waste, and food waste leachate as substrates. The organic solid wastes were collected from M city, where the daily productions of sewage sludge, swine waste, and food waste leachate were 178 ton/d, 150 ton/d, and 8 ton/d, respectively. Both swine waste and food waste leachate showed superior methane yields, methane productivities, and organic pollutant removal efficiencies compared to sewage sludge. Co-digestion of the total amounts of organic solid wastes would enhance methane production by 5.60 times $(530\;m^{3}\;CH_{4}/d\;{\rightarrow}\;2,968\;m^{3}\;CH_{4}/d)$. However, it also increase the amount of digestate by 1.88 times with 3.79 to 4.92 times higher pollutants (chemical oxygen demands total nitrogen, and total phosphorus) loading rates. Co-digestion of organic solid wastes is a valid strategy to enhance the performance of an anaerobic sludge digester and the energy independence of a wastewater treatment plant. Anyhow,the increment of digestate with higher pollutant loading would need a careful counterplan in the operation of the main stream of the treatment plant.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.2
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• pp.7-30
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• 1998

Generation and recycling potential of organic waste in Korea were estimated. Status of organic waste composting and compost utilization also were surveyed to promote the recycling of organic waste. From 1994 to 1997, generation of garbage decreased gradually while recycling rate increased due to positive governmental strategy. During the same period, livestock waste increased 11.2%. Municipal wastewater sludge was generated 3,500 ton/day which was 0.03% of wastewater treated in 1996. The energy Potential of industrial organic waste was estimated to 288 million TOE which was 1.75% of the nationwide first energy consumption in 1996. Recycling of industrial sludge was low to 31%, while recycling of animal waste, plant scraps, and wasted paper were relatively high over 50%. Industrial sludge should be recycled more as it was the most part of industrial organic waste. Conventional composting materials were mainly livestock waste, food processing waste, fishery waste, sawdust, and nightsoil. Garbage and sludge have been composted recently. 420,000 tons of compost in 1996 were produced by 288 makers, the most of which were utilized in agriculture. It was suggested that separated collection, compost standard, and quality management should be provided to promote the composting of organic waste.